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The_Battary_guy

macrumors newbie
Original poster
Aug 19, 2020
10
3
batt.png

It's almost 4 months into my mba and Coconut battery indicates battery capacity at 91%, Is that normal.


But system information says it's at 100% wtf is goin on?


Screenshot 2020-10-05 at 7.13.15 PM.png
 

CheesePuff

macrumors 65816
Sep 3, 2008
1,454
1,574
Southwest Florida, USA
Do you have optimize battery charging enabled in system preferences? If so, that is why.

edit: sorry, its called Battery health management in macOS, under system preferences > energy saver > battery health button at the bottom
 
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The_Battary_guy

macrumors newbie
Original poster
Aug 19, 2020
10
3
Do you have optimize battery charging enabled in system preferences? If so, that is why.

edit: sorry, its called Battery health management in macOS, under system preferences > energy saver > battery health button at the bottom
Yes I've enabled it.
 

ascender

macrumors 603
Dec 8, 2005
5,019
2,896
So long as you're still getting the expected use-time out of the battery per charge I wouldn't worry about it. If it starts to drop off, then I'd be worried.

There is such a thing as too much information these days.
 

throAU

macrumors G3
Feb 13, 2012
9,089
7,242
Perth, Western Australia
So long as you're still getting the expected use-time out of the battery per charge I wouldn't worry about it. If it starts to drop off, then I'd be worried.

There is such a thing as too much information these days.

Well, i'm not really given that i've got 11-12 percent less battery capacity than when it was new...

It was fine for a couple of months, but in the past few weeks its dropped by about 4-5 percent.

I've just hit charge 60 cycles on it, battery manufacture date: 9th Jan 2020.
 
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theSeb

macrumors 604
Aug 10, 2010
7,466
1,893
none
Threads like this make me wish I had kept coconutBattery installed so that I could see my history. I do not bother with following all the care guidelines that have been posted on these forums for many years. Sometimes my MacBooks live on the charger for months. Sometimes they get left behind in a cupboard for months or even a year.

This is the current battery state for my 2012 MBP

MBP battery.png


I am trying to remember what happened to the battery health in the first years for all of the MacBooks I had. I am pretty sure that initially they dropped to around 90% quite quickly, but I am not entirely sure how quickly. In my view the numbers mentioned above are somewhat concerning, considering the age of the machines. I reckon wait till around they are 10 months old and check then and if they are lower than 90%, then I would definitely be on the call to Apple support.
 

theSeb

macrumors 604
Aug 10, 2010
7,466
1,893
none
Like I said above... all my Macs have dropped to around 90% fairly quickly and then stayed there for ages. Also you will notice that the battery health goes up and down by a few percent if you start tracking it. Nothing to worry about.
 

throAU

macrumors G3
Feb 13, 2012
9,089
7,242
Perth, Western Australia
Scratch that...
Screen Shot 2020-10-26 at 7.56.54 pm.png





So... according to this:

It may charge only to 80 percent if it thinks you're on AC power too much. SO maybe my battery health will drop to 80 percent, pretty quick? Hmm...
 
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theSeb

macrumors 604
Aug 10, 2010
7,466
1,893
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That does look abnormal. In comparison this is my 5 year old Macbook (not Air) at 84.5%

Apple's battery health management is supposed to stop the aging and not make it drop to 80 percent quicker.

macbook.png
 

throAU

macrumors G3
Feb 13, 2012
9,089
7,242
Perth, Western Australia
I guess what I am wanting to know is this:
does the health management work via telling the OS the max battery capacity is less than it really is so it doesn't charge as much, and then THIS in turn leads to erroneous battery health readings?

If that's what it is doing... fine.

If that's not exactly how it works.... this battery in the 2020 machine is total trash.


And yah. my 2011 machine (and my 2015) still has better battery health.
 

theSeb

macrumors 604
Aug 10, 2010
7,466
1,893
none
Oh, I see what you mean. No, I don't believe it does, but you could check it yourself. Get coconutBattery (it's free) or go into about this mac and then system report. In the power section you will see your total capacity in mAh. Take note of that number and then switch off battery health management. Probably best to restart. Then go back to check the total capacity again. I suspect that it does not modify this number and instead it does indeed only charge around 80% quickly, then slowly or not at all, depending on what it learns about your use. For example my iPhone now knows that it must finish charging by 6:30 AM every day.

This is mentioned here
battery.PNG
 

throAU

macrumors G3
Feb 13, 2012
9,089
7,242
Perth, Western Australia
Yeah, I've read the docs, but apple haven't been forthcoming about what it does to that number. I might try turning it off for a while and reboot, etc.

I did turn it off, noticed no change, but I can't remember if I rebooted.

In the middle of a backup at the moment, but will give it ago.

No need for coconut battery, iStat does it, as does the system report, its a simple case of current max capacity vs. design capacity figures.

I'm thinking/hoping it may be trending towards giving me 80% max capacity based on usage. If that IS what it is doing... fine I guess. But they don't document this in any real sane manner.
 

theSeb

macrumors 604
Aug 10, 2010
7,466
1,893
none
They way you describe you think it may work does kind of sound like a "magical" thing Apple might just do, but I have my doubts.
 
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throAU

macrumors G3
Feb 13, 2012
9,089
7,242
Perth, Western Australia
They way you describe you think it may work does kind of sound like a "magical" thing Apple might just do, but I have my doubts.

So do i.... but it does sound like the sort of... *waves hand* "it's magical it just works" crap they'd pull.

The only hint is in the docs where they say it may result in your Mac showing battery service required "early".
 
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ghanwani

macrumors 601
Dec 8, 2008
4,778
6,073
Looks a bit weird, but can’t suggest anything. If it drops below 80%, that’s when Apple may replace it.

My 2019 MBA is showing 86% at 526 cycles and 14 months.
 

Need_Advice

macrumors newbie
Nov 9, 2020
27
10
Guys, just think about what Battery Health Management does or read what the text in this menu says:
1605773797841.png


The battery is being cared of by not charging to its maximum. Sure, it charges to 100%, but 100% in this case means less per cent of your max capacity. In the long term this is more gentle for the batteries.

Btw mine is at 91,5% after 120 cycles. Before the update in July it was at 96-98%. I'm pretty sure the strong drop is caused by Health Management of the July update. Watch your History in CoconutBattery and you'll see a strong drop from one to the other day. The day you updated your device.
 

thadoggfather

macrumors P6
Oct 1, 2007
15,880
16,744
I'm at 88% with 100 charges.

Have warranty until end of April. Almost certainly going to push for a battery replacement before then

This doesn't seem right. Hopefully as it approaches the sub-80% with under 1000 charges which it certainly seems on the trajectory for
 

ghanwani

macrumors 601
Dec 8, 2008
4,778
6,073
I'm at 88% with 100 charges.

Have warranty until end of April. Almost certainly going to push for a battery replacement before then

This doesn't seem right. Hopefully as it approaches the sub-80% with under 1000 charges which it certainly seems on the trajectory for
It can remain steady for long periods, e.g. mine is showing 85%-88% between 258 and 537 cycles!

I am planning to get the new MBA as soon as I get some time off work. Battery life on this one now gets me about 5-6 hours, less if on conf calls.
 

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